Abstract
The objective of this study was to examine practice effects and longitudinal cognitive change in a population-based cohort classified as clinically normal at their initial evaluation. We examined 1390 individuals with a median age of 78.1 years and re-evaluated them up to four times at approximate 15-month intervals, with an average follow-up time of 5 years. Of the 1390 participants, 947 (69%) individuals remained cognitively normal, 397 (29%) progressed to mild cognitive impairment (MCI), and 46 (3%) to dementia. The stable normal group showed an initial practice effect in all domains which was sustained in memory and visuospatial reasoning. There was only a slight decline in attention and language after visit 3. We combined individuals with incident MCI and dementia to form one group representing those who declined. The incident MCI/dementia group showed an unexpected practice effect in memory from baseline to visit 2, with a significant decline thereafter. This group did not demonstrate practice effects in any other domain and showed a downward trajectory in all domains at each evaluation. Modeling cognitive change in an epidemiologic sample may serve as a useful benchmark for evaluating cognitive change in future intervention studies.
Original language | English (US) |
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Pages (from-to) | 1247-1264 |
Number of pages | 18 |
Journal | Clinical Neuropsychologist |
Volume | 27 |
Issue number | 8 |
DOIs | |
State | Published - Nov 1 2013 |
Keywords
- Alzheimer's disease
- Cognition
- Memory
- Mild cognitive impairment
- Practice effects
ASJC Scopus subject areas
- Neuropsychology and Physiological Psychology
- Developmental and Educational Psychology
- Arts and Humanities (miscellaneous)
- Clinical Psychology
- Psychiatry and Mental health